Some reflection...

There are a few issues that have been plaguing me since the beginning of construction. Looking back over the course of the project I would have changed a few things from the beginning which would have made this whole endeavor much simpler. First and foremost I really did little planning prior to drilling holes, mounting tubes, and soldering. This was my biggest mistake. The tubes are too close together which made some of the soldering extremely difficult...and sometimes painful. I wish I had known a little bit more about circuit diagrams and design before I started making "permanent" connections. If I had planned a little better from the beginning, and known a little more about circuit design, construction would have been much easier. In the end though it is almost as though I took a crash course in circuitry which is exciting. So, to anyone attempting to construct something of this caliber...plan first!

A test picture

Here is a pretty interesting picture. This is the device I am currently working on using to test and make sure all of the tubes are in proper working condition:

A great series of videos.

Testing! and ... testing

Things are now in the "debugging" phase. Here are some images of the "completed" product and the power supplies. On the left we have two power supplies (stacked on top of each other) providing 50W of power. On the right the solo power supply is providing 10-12W of power (depending on how I feel while testing) which is providing power solely to the tubes. I have been testing and rewiring parts of the theremin for a few weeks now. One interesting fact to note is that outlets produce a 60Hz signal. I found this out, as well as learned what the capacitor in this circuit directly prior to the speaker is doing, when I found a perfect sinusoidal wave occurring before this capacitor. It turns out this capacitor acts as a high pass filter with is cutoff most likely set around 60Hz to filter out the frequency that is coming from the power supplies. This is capacitor C13 on page one of the schematics (.01μF). Lately during my testing what I have been trying to do is find the signal being generated by the volume oscillator and trace that to the VCO and find where the signal is breaking apart. I think what I will try next is the same signal tracing but this time from the frequency signal generated by the right antennae.

Construction "complete"

After all the soldering has been finished:

Schematics

Just realized I probably should have posted these months ago...

Here is a link to the site I have been using: http://home.att.net/~theremin1/126/126.htm

Soldering day 2

After a long day of soldering.

Construction continues.

Soldering day 1.

Something unreal.

Though this isn't exactly what the theremin I'm constructing will do...this video is out of this world.

Construction has begun!

So, construction has officially begun. Here is the first image. In this picture we have the mounts for the vacuum tubes that will be used in the construction mounted on an old clipboard.

Couple more awesome videos.

Crazy! In theremin form.

http://www.youtube.com/watch?v=mW0B1sipLBI

Legend of Zelda

http://www.youtube.com/watch?v=nJYho56INKU

A little history!

A theremin is an electronic musical instrument controlled by the proximity of the player's hands to two external antennas. Invented by the Russian physicist Leon Theremin in 1919, while conducting research in proximity sensors, the theremin marked the beginning of electronic music ("Theremin"). The player's proximity to one antennae controls the frequency of the emitted pitch while the proximity of the other hand controls the volume. To produce a signal the theremin implements the heterodyne principle, which in radio and signal processing is generating new frequencies by mixing or multiplying two oscillating waveforms ("Hetrodyne"). The circuitry of the instrument consists of two radio frequency oscillators with one oscillating at a set frequency. The second frequency is controlled by the player's distance from the pitch controlling antennae. In this circuit the hand of the performer acts as the grounded plate in a variable capacitor of an LC circuit. It is the difference in the frequency between the preset oscillator and the position of the player's hand that allows for the creation of sounds in the audible range of frequencies (20 - 20,000Hz) ("Theremin - GHN"). This signal is then passed to a loudspeaker. For the control volume of the theremin the same variable capacitor circuit is set up with the player's hand detuning the second oscillator which effects the amplification circuit ("Theremin - GHN").


"Theremin." Wikipedia, the free encyclopedia. N.p., n.d. Web. 16 June 2009.

http://en.wikipedia.org/wiki/Theremin.

"Heterodyne." Wikipedia, the free encyclopedia. N.p., n.d. Web. 16 June 2009.

http://en.wikipedia.org/wiki/Heterodyne.

"Theremin - GHN." Main Page - GHN. N.p., 2 Sept. 2008. Web. 16 June 2009.
http://www.ieeeghn.org/wiki/index.php/Theremin.

Welcome

Hello! Welcome to my theremin blog. Here you will find interesting information about theremin's, links to cool theremin videos, as well as a detailed account of the construction of a vacuum tube theremin. Enjoy!